Safety device for rotary drilling rigs



y 1940. 1'. A. TAYLOR ET AL 2.200.210

SAFETY DEVICE FOR ROTARY DRILLING RIGS Filed Sept. 28, 1938 2Sheets-Sheet 1 May 7, 1940. T. A. TAYLOR ET AL 2 SAFETY DEVICE FORROTARY DRILLING RIGS Filed Sept. 28, 1958 2 Sheets-Sheet 2 6 9 zzz fi 4& 5 fi 21! 371/ Z5! x: uc/n-hvcs 97d 11 15.5 fq mdmom m m Patented May1, 1940 2,200,2l

umrso STATES PATENT OFFICE sax-arr navrcn FgitGgoTAltY DRILLING Tom A.Taylor and Charles F. McComas, Olney,

Application September 28, 1938, Serial No. 232,218

2 Claims. (Cl. 254-187) the slack, the other end portion of the ropebeing said clutch head at 9, and the lower end thereof we connected tothe drill pipe or other object to be operatively engaged at ill with arod ii, whereby drawn up, said line shaft having a clutch which uponmovement of said rod in one direction or is thrown in and out to driveand release the the opposite direction the clutch head will be some,moved to render the clutch operative or inoper- Due to the fact that theattendant or cat ative as the case may be, thereby setting the u a Theinvention consists in the novel construcbranch 22' communicating with avalve chamber 80 tion and combinations of parts as hereinafter set atone end and one side of said casing and a forth in the claims. branch'22" communicating with a valve chamber In the accompanying drawings, atthe other end and other side of said casing. A Figure 1 is an end viewof the invention as pip connects a central h mber 23" at one I appliedto a rotary drilling rig. Figure 2 is a side side of said casing withthe outer end of cylinder 85 view of the same on a larger scale, withthe i5, and a pipe 3 connects the central chamber treadle depressed torender the clutch operative, at the other side of the casing with theouter d the connections of the pipes to the aligned cylof the cylinderl4.

inders being diagrammatic and parts being broken A treadle control lever2| has connection with m away. Figure 3 is a detail central longitudinalthe valve stems and is adapted upon actuation section of the powertake-off pulley, showing the to close the valve ports of the chambers atone clutch and the collar. Figure 4 is a detail secend of said casingand open the valve ports of th ,tional view, partially diagrammatic,showing the chambers at the other end of said casing, thereby alignedcylinders, the valve device, and the pipe admitting fluid pressure tocylinder l5 to p 51- connections, the treadle being shown as releasedtively operate lever 1 in one direction and render 46 to render theclutch inoperative. the clutch oper t e. Upon release of the treadl Inthese drawings, the numeral designates the co lever the valves 20 areted by their line shaft of a draw works or rotary drilling rig, p s 2|to normal position to close the valve whereon is mounted apower-take-oif or cat ports of the chambers at the other end of the headpulley 2, one end portion of a rope being casing and open the valveports of the chambers 5 adapted to be coiled around said pulley and theat the opposite end of the casing, thereby admitloose end of the ropepulled by the attendant or ting fluid pressure to cylinder M topositively cat head" man as described. operate lever I in the oppositedirection and ren- The pulley 2 is loosely mounted on the line der theclutch inoperative, the fluid pressure in I shaft, a collar I beingfixedly mounted on an end the cylinders having exhaust through ports 20"II The invention relates to draw works or rotary drilling rigs, whereinthe line shaft is provided at one or both ends thereof with a powertake- ,off or "cat head" pulley, it being customary to spin or draw updrill pipe and various other objects by coiling one end portion of arope around said pulley and the attendant or "cat head" man pulling uponthe loose end portion of the rope to keep the coil tight on the pulleyand to take in head" man is liable to become fouled in the rope which heis pulling, it is an object of the invention to provide a safety devicefor rendering the clutch so operative and inoperative that said pulleymay be stopped instantly by the attendant the instant the rope isfouled, said stopping of the pulley being either voluntary orinvoluntary on the part of the man pulling the rope. Another object isto provide such a safety device adapted to be installed on any size ortype of draw works or rotary drilling rig with little difliculty.Another object is to provide a simple and inexpensive device of thisdescription. Other objects and advantages will appear hereinafter.

of the line shaft adjacent said pulley and a clutch head 4 being fixedlymounted or keyed to the line shaft adjacent the other side or end of thepulley, a clutch lining 5 being interposed between said collar and thepulley and a clutch lining 6 being interposed between said clutch headand the pulley.

A lever 1, fulcrumed at 8 has the upper end thereof operativelyconnected or engaged with pulley in rotation with the line shaft orreleasing the pulley from the shaft.

The rod II is a connecting rod between two pistons l2 and 13, saidpistons working in aligned cylinders i4 and IS. A valve casing 23 isprovided said valve chambers and controlling said ports 25 are fourvalves 20, each couple of valves being aligned and having a stem 20connecting the same and having a retracting spring 2i. A pipe 22connected to a source of fluid pressure has a of those of the valvechambers with which the branches of the pipe 22 have no connection.

The treadle control lever 2| is adapted to be depressed by the foot ofthe attendant pulling the end portion of the rope as aforesaid, and uponremoval of his foot either voluntarily or involuntarily from said lever,the valves will be retracted by their springs to instantly render theclutch inoperative.

The clutch lining 5 is duplicated upon the collar and the pulley and theclutch lining 6 is duplicated upon the clutch head and the pulley,operation of lever 1 serving to frictionally engage and disengage theclutch linings to render the clutch operative or inoperative as the casemay be.

The take-oil pulley or cat head is provided with suitable anti-frictionbearings 24, and a countersunk Alemite fitting 25 for applying lubricantto said bearings.

In practice it is found that the take-01f pulley or cat head may bestopped instantly by the man pulling the rope the instant the rope isfouled by removal of his foot from the treadle control lever 2|, and ifhe does not get his foot off the treadle control lever quick enoughhewill be pulled oiI the treadle by the rope, whereupon the pulley will beinstantly stopped due to the clutch being rendered inoperative.

The clutch will be rendered operative and inoperative substantiallyinstantaneously upon depression of the treadle 2| and release thereof,and the friction clutch described will pull all that a one and one-halfinch diameter rope will stand, this being the largest rope for thispurpose used upon a rotary rig. All parts described will operate welland efl'lciently.

We claim:

1. In a rotary drilling rig having a line shaft provided with a cat headpulley loosely mounted thereon, a normally inoperative clutch betweensaid shaft and said pulley, and means for rendering said clutchoperative and inoperative comprising a lever having engagement with amember of said clutch; the operating means for said lever being positivein both directions and including aligned cylinders, pistons workingtherein and having a rod connecting the same, said lever havingengagement with said rod, and

means for admitting fluid pressure to one 0! said cylinders to rendersaid clutch normally inoperative and for admitting fluid pressure to theother cylinder to render said clutch operative comprising a valve devicehaving spring retracted valves and a control lever for adjusting saidvalves against the tension of their springs, said valves being retractedby their springs to render the clutch inoperative upon voluntary orinvoluntary release of said control lever.

2. In a rotary drilling rig having a line shaft provided with a cat headpulley loosely mounted thereon, a normally inoperative clutch betweensaid shaft and said pulley, and means for rendering said clutchoperative and inoperative comprising a lever having engagement with amember of said clutch; the operating means for said lever being positivein both directions and including aligned cylinders, pistons workingtherein and having a rod connecting the same, said lever havingengagement with said rod, and means for admitting fluid pressure to saidcylinders including a valve casing provided at each end thereof with twovalve chambers located at opposite sides of the casing, and with twocentral chambers having ports communicating with said valve chambers,four valves controlling said ports and located in said valve chambers,each couple of valves being aligned and having a stem connecting thesame and provided with a retracting spring, the source of fluid pressurehaving a branch communicating with a valve chamber at one end and oneside of said casing and a branch communicating with a valve chamber atthe other end and other side of said casing, a pipe connecting a centralchamber at one side of the casing with the outer end of one of saidcylinders, a pipe connecting the central chamber at the other side ofthe casing with the outer end of the other of said cylinders, and acontrol lever having connection with the valve stems and adapted uponactuation to close the valve ports of the chambers at one end and openthe valve ports of the chambers at the other end of said casing, saidvalves being retracted automatically upon release of said control lever.

. T. A. TAYLOR.

C. F. MpCOMAS.

